The Active Attacks occur for a variety of reasons, sometimes they are planned and other times not. Here, we show the timing of Active Attacks from 2000 to 2023, a critical element for premeditated attacks with the goal of maximizing casualties. As the plots demonstrate, some dimensions of time are more informative than others.
By Year
There appears to be more events in the last five years (mean = 46) than the first five years (mean = 8) or second five years (mean = 16); however, this may be an artifact of media coverage. Events that occurred during the first part of this data collection period likely did not get the national coverage that they do now. Furthermore, technology and search engines have improved dramatically over the 24 years of this data collection period.
By Month
In contrast to the obvious upward trend in attacks across years, there appear to be only a modest trend related to months of the year. Active Attacks tend to peak during the warmer months of the year (e.g., April through August account for 47.2% of attacks), though this trend is not a strong one. The relationship with temperature is similar to trends observed for certain types of violent crime (e.g., aggravated assault, homicide) that also tend to peak during the warmest parts of the year.
By Day of the Week
Active Attacks share no observable association with day of the week. This can be seen by the flat distribution of attacks across the week. So while there may be trends by year and month, attacks appear to be nearly equally likely on any given day of the week.
By Hour of the Day
Active attacks tend to cluster around midday. While attacks that begin at midday exactly are relatively infrequent (only 3.9% of attacks), the majority of attacks occur immediately before midday (8-11am hours account for 25.4% of attacks) or after midday (1-4pm hours account for 24.3% of attacks).
Many in the media attempt to create a profile describing the “average” attacker. The data do not support a profile beyond sex and number of attackers. Attackers were male 96.2% of the time. Furthermore, the attacker commits the attack by him/herself 97.5% of the time. Beyond these characteristics, attackers are somewhat more varied.
Attacker Race/Ethnicity
Most attackers were either Caucasian (46.2%) or African American (30%). All other racial/ethnic groups (e.g., Latino, Asian, Middle Eastern) only accounted for around a quarter of attackers (23.8%).
Attacker Age
While the median age of attackers was 31.5 years old, attackers ranged in age from 12 to 88. Attackers in their twenties were the most plentiful group compared to any other decade of life. The age-trend of attackers adheres to the classic “age-crime curve” observed for nearly every crime type, peaking in late adolescence/early adulthood and steadily declining throughout the rest of the life course.
Weapon Type
Active attacks can be carried out using any weapon though, in reality, only a very small minority of attacks (6.2%) were carried out using weapons other than firearms (e.g., knife, vehicle). Among types of firearms, handguns made up a clear majority (56%), while rifles (e.g., AR15s) and shotguns were used in 28.3% and 8.1% of the time, respectively.
Defining where an attack occurred can be difficult. For instance, on January 8, 2011 a shooter attacked a meeting for U.S. Representative Gabrielle Giffords. This attack happened in the parking lot of a local Tucson grocery store. Had the attack happened in the store it would have been classified as a business event; however, since the attack occurred in the parking lot it is coded as an outdoor event. Bear these fine distinctions in mind when examining the visualizations in this section.
Location Type
As seen here, the plurality of events happen at places of business (42.8%). Places of business include factories/warehouse, retail locations, and office space. Around a quarter of attacks (26.8%) happened in public (outdoor) spaces. Schools were attacked 76 times (13.4%). These events are aggregated and include attacks on all types of educational facilities, including K-12 and institutes of higher education. Lastly, 97 attacks (21.7%) happened at “Other” locations (e.g., houses of worship).
Relationship to Location
In a majority of attacks (64.1%), the attacker(s) had no prior association with the attack location. Despite businesses being the most common attack location, only 10.6% of attackers were carried out by current/former employees. While only 21 attacks were carried out by current/former students, these attacks accounted for 27.6 attacks on schools. The final grouping included all remaining relationship types (21.7% of attacks), some of which were obscure (e.g., former patient) or were “indirect”, that is, their spouse or other family member had the primary association with the attack location.
Location Type and Time of Day
When grouped by location type, the tendency of attacks to occur around midday is still observable, though it is modest. The most noticeable trend can be see with attacks at schools, where there is a strong tendency for attacks to occur during the morning ours prior to midday.
There were 3,917 casualties of active attacks between 2000 and 2023. Of these, 1,383 people died. The visualizations in this section examine these fatalities.
Attacks vs. Fatalities by Year
Attacks and total fatalities have been increasing over the course of data collection (2000-2023). For specific years, however, there are noticeable spikes in the number of death. These spike often correspond to some of the more well-known attacks. For example:
Of note, while the number of active attacks did not decrease during the COVID-19 pandemic, the lethality of attacks did decrease to less than half the number of any of the four years previous. In 2021, however, the number of attacks increased and the number of deaths returned to pre-pandemic levels.
Fatalities per Attack (Interactive)
Most attacks (96.1%) resulted in fewer than 10 fatalities, with 31.9% of attacks resulting in no deaths at all. Hover over the points on this plot to get information about that specific attack.
Fatalities per Weapon Type (Interactive)
While most attacks (56%) were committed using handguns, the only such attack that resulted in more than 20 fatalities occurred at Virginia Tech, 2007. Attacks using rifles accounted for all of the remaining attacks that surpassed 20 deaths. Hover over the points on this plot to get information about that specific attack.

Static plot (.png)
Interactive plot (.html)
Static plot (.png)
Interactive plot (.html)
Active attacks have been recorded in 46 states and the District of Columbia. States with no recorded attacks include Delaware, Montana, Rhode Island and Wyoming. While most states have at least some number of attacks, the number of attacks (and fatalities) tend to cluster geographically. The visualizations in this section show that geographic dimension.
Attacks & Fatalities by State (Interactive)
The number of active attacks in a state strongly corresponds to the number of fatalities.
Attacks & Fatalities by Year (Interactive)
Static plot (.png)
Interactive plot (.html)

It is the mission of the Research Ring at ALERRT to make the Active Attack Data as freely accessible as possible. Please feel free to explore the raw data in the window to the right or download as a .csv file using the download button below.
The dataset is organized so that each row corresponds to a unique active attack. This means that some variables, like attacker characteristics, need some special handling. Because some events involved multiple attackers, variables like age, race/ethnicity, and sex, are given a special suffix (e.g., _1, _2, _3) that correspond to specific attackers. For an attack with only one shooter, the demographic variables ending in _2 and _3 will contain missing values. The suffixes were assigned randomly and should not be taken as an indication that individuals described by variables ending in _1 were somehow more central to the attack than the other people involved.